SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9978b8052b1dde944f2d096dc3f48fbb7841bac8e05d90952c6b7136db2ef17a' 
  AND token = 'ZSCkVL9QstgdCCt2cQ5BBQ2gqoHEZPyZZOjAm4RLtgs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}